Princeton University Star Formation/ISM Rendezvous (SFIR)

TITLE AND ABSTRACT ADDED. Solar prominences are long-lived cool and dense plasma curtains in the hot and rarefied corona. The physical mechanism responsible for their formation and especially for their internal plasma circulation has been uncertain for decades. The observed ubiquitous down flows in quiescent prominences are difficult to interpret as plasma with high conductivity seems to move across horizontal magnetic field lines. Here we present three-dimensional (3D) numerical simulations of prominence formation and evolution in an elongated magnetic flux rope as a result of in-situ plasma condensations fueled by continuous plasma evaporation from the solar chromosphere. The prominence is born and maintained in a fragmented, highly dynamic state with continuous reappearance of multiple blobs and thread structures that move mainly downward dragging along mass-loaded field lines. The prominence plasma circulation is characterized by the dynamic balance between the drainage of prominence plasma back to the chromosphere and the formation of prominence plasma via continuous condensation. Plasma evaporates from the chromosphere, condenses into the prominence in the corona, and drains back to the chromosphere, establishing a stable chromosphere-corona plasma cycle. Another form of cool and dense plasma in the corona is coronal rain, which forms through similar mechanism in-situ and drain down arched pathways along loops near active regions. We present 3D simulations of coronal rain in a bipolar arcade with preliminary results.